Powell bars habeas relief if the state fails to raise Stone in the district court, or whether Stone announced a categorical rule that Fourth Amendment claims are not cognizable on habeas review absent a showing that the state prisoner was denied a full and fair opportunity to litigate the issue in state court; (2) whether the decision of the United States Court of Appeals for the Second Circuit, in relying on studies that were not part of the state court record, conflicts with this Court's… [read post]